56666651 has 4 divisors (see below), whose sum is σ = 56704032. Its totient is φ = 56629272.

The previous prime is 56666579. The next prime is 56666653. The reversal of 56666651 is 15666665.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 56666651 - 2¹⁰ = 56665627 is a prime.

It is a super-5 number, since 5×56666651⁵ (a number of 40 digits) contains 55555 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 56666599 and 56666608.

It is not an unprimeable number, because it can be changed into a prime (56666653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16316 + ... + 19481.

It is an arithmetic number, because the mean of its divisors is an integer number (14176008).

Almost surely, 2^56666651 is an apocalyptic number.

56666651 is a deficient number, since it is larger than the sum of its proper divisors (37381).

56666651 is a wasteful number, since it uses less digits than its factorization.

56666651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37380.

The product of its digits is 194400, while the sum is 41.

The square root of 56666651 is about 7527.7254864932. The cubic root of 56666651 is about 384.0984154397.

The spelling of 56666651 in words is "fifty-six million, six hundred sixty-six thousand, six hundred fifty-one".